273 vs 318

Here is my take. I have done several cars with the 273 and you can't beat them.


273 2 barrel CR is 8.8 to 1. If you use the 66-67 closed chamber heads and shave the heads you could be looking at around 9.1 to 9.3 CR depending on head gasket thickness.

The 273 heads flow quite well on that small motor with some minor mods. A little porting and clean-up of the bowls, 5 angle valve job and going with a 1.84 intake (cut down 360 MP 1.88 valve) and a 1.72 (ferra valve) will yield some flow and velocity numbers the motor can handle. Intake valves larger than 1.84 will cause shroding problems unless the bores are notched.

The Isky E-4 cam is a good choice. Has a nice idle but will pull hard. Of course it's a solid cam and you will need adjustable valve train. The stock adjustables work fine.

The Edelbrock D4B wins hands-down as far as the 273 in my opinion. There are some mods you can make to that manifold. The Carter 9635/9636 works real well on a 273.

Of course all other mods such as electronic ignition, good plug wires etc. will help. On the converter issue, one way to solve the small centering journal on the end of the crank is to have it machined to accept the larger converter centering hubs.

One thing to remember, this little motor likes low gears, the more, the better. 3:55 up is your best choice. In your car, a set of 3:91's would be killer.

I forgot to mention that the 904 is a killer tranny for the 273. you can put the low 1st and 2nd gear in that tranny with a 2500 stall converter and you'll leap out of the hole with that combo.